Electric switch.



g gggi k E. M. HEWLETT.

ELECTRIC SWITCH.

APPLICATION FILED SEPT. 1911.

1,155,814. Patented 001 5,1915.

2 SHEETS-SHEET 1. A?

l/vvervtorr Edward M.Hew/ett Wit/vesses:

Mums rc'rus, m. 1.1mm. \u'wmon. o. 1;

His fitter/veg.

To all whom it may concern:

EDWARD unnwmrr', or scnnNEcmnY, NEW

YORK, ASSIGNOR ro GENERAL nnn'c'rmc COMPANY, A oonrone'rxon or NEW YQRKmELECTRIC swrrcn.

originalapplication med July 15,1910, Serial No. 572,123; Divided-andthi szapplication area September 1} .m' o 1911. Seria1No.647,143 e f IBe it .kn'ownthat I, EDWARD M. HEWLETT.

a citizenrof the United States, residingat Schenectady, county ofSchenectady, State of'Ncw York,- have invented certain new? the drawingsand useful Improvements in Electric witches (divisionof inyapplicationfiled July 15., 1910, Serial No. 572,123,) of which the following is avspecification. Y

My invention relates to electric switches," particularly t0 switches foropening circuits carrying large amounts of energy, and object is toprovide an improved switch which will open circuits carrying largeamounts of energy, and in which the arc formed on separating thecontacts is promptly and effectively extinguished.

lVhen an electric'switch is connected to a circuit. carrying a largeamount of energyand particularly if the voltage of the current is high,a persistent and dangerous arcis formed when the contacts of the switchare separated, even thoughthe contacts separate 1n a vessel containingsome suitable insulating fluid, such as oil. In accordance with myinvention; the are formed on separating the contacts is drawn into somesuitable device inwhich insulating fluid is put under great pressure bythe arc and on account of its pressure promptly extinguishes the arc.Various devices may be used which tend to disrupt and extinguish the.are when the arc is drawn into them, but the preferred device is asubstantially closed pressure retaining vessel mounted in such aposition that, as the contacts separate, the arc is drawn into thepressure retaining w'essel, whereupon the oil or other insulating fluidin the pressure retaining vessel is put under pressure. by the arc andextinguishes the -Various forms of arc extinguishing pressure retainingyessels are shown in my application for electric switches, SerialNo;filed July- 1-5, 1910. of which this;

572,123.; application 18- a: division.

iv inventiolrg-will b st beflunderstood; in

connection with the accompanyingdrawings which merely forpurposes. of;illustration show some-0fthe" arious for ns in which the invention maybe embodied and in which p Figure 1 is a longitudinal section of theform of switch in which the arc is drawn upward into the pressureretaining-vessel where it isextinguished; and Fig. 2 is a Specificationof Lettersrate nt.

extinguished.

centric layers by a concentric barrierAIof .9 carried in the head 'SOfthe switch. The

WVhen the contacts 7 and"8 are separated,

'the arc to extinguish it.

i Patented 001555,; 1915;

"longitudinal ect-ioa'gore e' rant bi "switch in which the arcfisfidrawndownward into the pressure retaining vessel. in whichut' is The sameparts in the switch s are indicate-din both the-fig ures by the samereference characters.

In therjform of switch shown in Fig.1, a suitable vessel 1, provi'dedwith a bottom 2 i and a top, 3,, contains oi or othersuitable insulatingfluid preferabl divided into" co'n-,

fiber or other suitable"insulating;material; A number of these barriersinlay-be 'used,. if desired. \Yhere oil is'usedas th I insulating'fluid, the tank 1 is filledfto fbri n Ethe level of the oil to thedotted'jliiie n the bot? toni of theparticularform ofswitch shown inFig. 1, there s mounted an "insulator 6 (of any suitable constructionwhich ."carries 0114 the upper end .a fixed contact- 7 connected to one,leadof the circuit-to bef controlled and cooperating with af'm'ovablecontact-'8; which is movably mountedin an insulator-:-

movable contact 8 i.smo ved. iinto and ontof' engagement with thefiitedfcont'actj'i-iri any rsuitable way, -prefe'rahly by 'mean's of. a;fluid pressure actuating mechanism such fas is outlined in dottedilinesin" the insulator-9, and comprising a piston" 10 rigidly con; nected tothe movable contact 8 an'dlslidahly mounted inwthe cylinder jll which"inturn is carried inthe insulator 9. Thelfp'iston .10 I and contactB; aremoyedupfanddown to open and close the circuit by means" of coinpressedair admitted the cylinder" 11 .through'supply pipes 12, yli chf in. turnare controlled by any suitable; alveinechanisrn piston 10 and contact 8'into the stationarycontact 7 and thence through the circuit" .100 anarcis formed and in'accordance with'my inyention the arc extinguished bybeing drawn intooperative relation to an arce'x tinguishing device,preferably a strong res;- sure retaining chamber or Vessel-fcontaining"insulating fluidtjsucli a'sloilj into which'l th arc is, drawn as theswitch opens'and ink whicli' the oil or otherinsulating' fluid put underpressure by the arcis directed against In the form of no not shown. Thecylinder and" piston 10 a a reiconnected to the Otlierlead'o'f thecircuit mnd currentflows through the cylinder 11 ing device is mom'ltedon'the insulator 9,

which carries onthe lower end a strong Pressure retaining pot or vessel.13made of any suitable material, preferably metal coveredwi thinsulation and provided with an insulating lining 14. The pot 13 isclosed atone end by the insulator 9 on which-it is mounted and at theother end by an insulating bottom or plate-15, heldin position by aflange 16 and perforated by, an opening 17 which is of less diameterthan the inner diameter-of the pct 13. When the switch is opened the"contacts Yand 8 separate in the outer-pot land as the contact 8 is movedupward 'thearc, if it persists, -is drawn into the pressure retainingpot or vessel 13 during the last portion of the movement of the contact8. As soon as the arcis drawn into the pressure retaining pct 13, theoil .or other insulating fluid in the .-'pot is at once put under greatpressure bythe action of the arc, whereupon the arc is compressed and atthe same time the oil which flows out of the pressure retaining potthrough the opening 17' in the plate 15 is directed against the arc andextinguishes it.

The switch shown in Fig. 2 is constructed with the insulator 6 and fixedcontact 7 .in' the top 3, and the insulator 9 and movable contact 8 inthe bottom 2, so that the movable contact moves downward. The insulator9 carrying the movable contact has on its upper end apressure retainingpot or vessel 13 constructed and operating in the same manner as thepressure retaining pct 13 of the switch shown in Fig. 1. The pressureretaining pct 13 of the switch shown in Fig. 2 is mounted on the upperendigof the insulator 9 which carries the movable contact 8. so thatthemovable contact 8 draws the arc into the pot 13 near the end of thedownward movementof that contact. In order to minimize the disturbanceof the oil in the main vessel and to assist in extinguishing the arc.the upper insulator 6 is provided on the lower end with a bell 18 whichsurrounds the fixed contact 7 and tends to "trap or hold the arc gasesgenerated as the contacts separate so that the arc gaseswvill not spreadout through the oil or other insulating fluid; and cause an arc to beestablished between the fixed contact and the walls of the vessel 1. Inthis form of switch the arc is extinguished by the action of the fluidput under pressure by the arc in the pressure retaining pct 13-, in thesame manner as in the switch shown in Fig. 1. Disturbance of the oil inthe vessel 1 is reduced to a minimum by the concentric barrier 4surrounding the movable contact 8. so that the main body of oil in thevessel 1 is;. -not disturbed by oil ejected from the pressure vesseladapted to contain insulating fluid, a

stationary contact mounted in said vessel, an inner pressure retammgvessel mounted in but insulated from sald outer vessel and having anopening in one wall thereof, and

a movable contact mounted in said inner vessel to move through theopening in said vessel'into engagement with'said stationary contact,said inner vessel being positioned to inclose said movable contact assaid movable contact reaches its final position as the switch opens.

25 An electric switch comprising an outer vessel containing insulatingfluid, a stationary contact mounted in one end of said vessel, aninsulator projecting into the other end of said vessel. an innerpressure retaining vessel mounted on said insulator and having anopening in one wall thereof, and a movable contact slidab'lv mounted insaid insulator to pass through said inner pressure retaining device andthrough said opening to -'cooperate with said stationary contact wherebysaid movable contact passes through said opening and into said pressureretaining vessel during the latter portion of its movement as the switchopens.

3. An electric switch comprising an outer vessel containing insulatingfluid, a stationary contact mounted in said outer vessel, a pressureretaining vessel mounted in but insulated from said outer vessel andhaving an opening inone wall thereof, and a movable contact mounted' insaid pressure re taining vessel to move through the opening in saidvessel to cooperate with said stationary contact, said pressureretaining vessel being mounted in said outer vessel near the end of thepath of opening movement of said movable contact in position to causesaid contact to pass through said opening and reach its final positionin said pressure retaining vessel as the switch opens.

In witness whereof, I have hereunto set mv hand this 31st day of August,1911.

; EDWARD M. HEWLETT.

lVitnesses:

BENJAMIN B. HULL, HELEN Oa'roan.

